A scientist at the USDA's Agricultural Research Center (ARS) said that breeding beans for heat tolerance would reduce the impact of heat stress in common beans, which would in turn help beans survive better in warmer climates. Most common beans (Phaseolus vulgaris), which include pinto, kidney, navy, red, black, and snap, are adapted to relatively cool climates. But in the United States, common beans are cultivated at average temperatures that can exceed 86 degrees Fahrenheit during the day. These hot summers can hinder the reproductive development of bean crops, which results in smaller potential yields, said ARS scientist Timothy Porch. However, by equipping beans with high-temperature adaptation traits, Porch hopes to be able to increase yields and reduce costs for consumers, as well as provide new genetic material that scientists can use for varietal development. "An important limitation is the narrow genetic diversity that's available," said Porch. "US breeding programs use less than 5 percent of available Phaseolus germplasm. New diseases, climate change, limited inputs, and market competition are all reasons to diversify the US bean germplasm base." Porch says that germplasm from the Tropics is the key to introducing the protective traits, as it harbors the vast majority of beans' genetic diversity Other traits Porch is working on include drought tolerance and disease resistance. Two major germplasm centers that Porch has worked with in his efforts to identify novel genetic traits include the International Center for Tropical Agriculture, in Cali, Colombia; and the ARS Western Regional Plant Introduction Station at Pullman, Washington. Porch is also using TILLING (Targeted Induced Local Lesions in Genomes), a technique based on identifying important genes in a population of mutated beans. "It's a direct and powerful approach to studying the function of important genes. Down the road, it can lead to development of new varieties with novel characteristics."